The present invention relates to a process and device to measure volume in which a volume to be measured is supplied with a first gas pressure p1, subsequently the pressure p1 is changed to a pressure p2 different from p1, and the volume is computed from the change over time of the gas pressure values.
It is difficult to measure the volume of an irregular or fissured cavity, especially one which is difficult to access or which leaks. This problem arises, e.g., when determining the compression volume of a combustion engine with which the compression ratio can be determined, taking the lifting volume into account. The efficiency of an internal combustion engine, and thus the consumption of fuel, is significantly influenced by the compression ratio so that precise knowledge of the compression volume is of great interest.